Merriam-Webster Collegiate Dictionary - gravity

 noun  (plural -ties)  Usage: often attributive  Etymology: Middle French or Latin; Middle French gravite, from Latin gravitat-, gravitas, from gravis  Date: 1505  1.  a. dignity or sobriety of bearing  b. importance, significance; especially seriousness  c. a serious situation or problem  2. weight  3.  a.  (1) the gravitational attraction of the mass of the earth, the moon, or a planet for bodies at or near its surface  (2) a fundamental physical force that is responsible for interactions which occur because of mass between particles, between aggregations of matter (as stars and planets), and between particles (as photons) and aggregations of matter, that is 1039 times weaker than the strong force, and that extends over infinite distances but is dominant over macroscopic distances especially between aggregations of matter — called also gravitation, gravitational force — compare electromagnetism 2a, strong force, weak force  b. acceleration of ~  c. specific ~